1 // Protocol Buffers - Google's data interchange format
2 // Copyright 2008 Google Inc. All rights reserved.
3 // https://developers.google.com/protocol-buffers/
4 //
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6 // modification, are permitted provided that the following conditions are
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8 //
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10 // notice, this list of conditions and the following disclaimer.
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13 // in the documentation and/or other materials provided with the
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18 //
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29 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30
31 // Author: ksroka@google.com (Krzysztof Sroka)
32
33 #include <google/protobuf/util/field_comparator.h>
34
35 #include <string>
36
37 #include <google/protobuf/descriptor.h>
38 #include <google/protobuf/message.h>
39 #include <google/protobuf/stubs/map_util.h>
40 #include <google/protobuf/stubs/mathlimits.h>
41 #include <google/protobuf/stubs/mathutil.h>
42
43 namespace google {
44 namespace protobuf {
45 namespace util {
46
FieldComparator()47 FieldComparator::FieldComparator() {}
~FieldComparator()48 FieldComparator::~FieldComparator() {}
49
DefaultFieldComparator()50 DefaultFieldComparator::DefaultFieldComparator()
51 : float_comparison_(EXACT),
52 treat_nan_as_equal_(false),
53 has_default_tolerance_(false) {
54 }
55
~DefaultFieldComparator()56 DefaultFieldComparator::~DefaultFieldComparator() {}
57
Compare(const google::protobuf::Message & message_1,const google::protobuf::Message & message_2,const google::protobuf::FieldDescriptor * field,int index_1,int index_2,const google::protobuf::util::FieldContext * field_context)58 FieldComparator::ComparisonResult DefaultFieldComparator::Compare(
59 const google::protobuf::Message& message_1,
60 const google::protobuf::Message& message_2,
61 const google::protobuf::FieldDescriptor* field,
62 int index_1, int index_2,
63 const google::protobuf::util::FieldContext* field_context) {
64 const Reflection* reflection_1 = message_1.GetReflection();
65 const Reflection* reflection_2 = message_2.GetReflection();
66
67 switch (field->cpp_type()) {
68 #define COMPARE_FIELD(METHOD) \
69 if (field->is_repeated()) { \
70 return ResultFromBoolean(Compare##METHOD( \
71 *field, \
72 reflection_1->GetRepeated##METHOD(message_1, field, index_1), \
73 reflection_2->GetRepeated##METHOD(message_2, field, index_2))); \
74 } else { \
75 return ResultFromBoolean(Compare##METHOD( \
76 *field, \
77 reflection_1->Get##METHOD(message_1, field), \
78 reflection_2->Get##METHOD(message_2, field))); \
79 } \
80 break; // Make sure no fall-through is introduced.
81
82 case FieldDescriptor::CPPTYPE_BOOL:
83 COMPARE_FIELD(Bool);
84 case FieldDescriptor::CPPTYPE_DOUBLE:
85 COMPARE_FIELD(Double);
86 case FieldDescriptor::CPPTYPE_ENUM:
87 COMPARE_FIELD(Enum);
88 case FieldDescriptor::CPPTYPE_FLOAT:
89 COMPARE_FIELD(Float);
90 case FieldDescriptor::CPPTYPE_INT32:
91 COMPARE_FIELD(Int32);
92 case FieldDescriptor::CPPTYPE_INT64:
93 COMPARE_FIELD(Int64);
94 case FieldDescriptor::CPPTYPE_STRING:
95 if (field->is_repeated()) {
96 // Allocate scratch strings to store the result if a conversion is
97 // needed.
98 string scratch1;
99 string scratch2;
100 return ResultFromBoolean(
101 CompareString(*field, reflection_1->GetRepeatedStringReference(
102 message_1, field, index_1, &scratch1),
103 reflection_2->GetRepeatedStringReference(
104 message_2, field, index_2, &scratch2)));
105 } else {
106 // Allocate scratch strings to store the result if a conversion is
107 // needed.
108 string scratch1;
109 string scratch2;
110 return ResultFromBoolean(CompareString(
111 *field,
112 reflection_1->GetStringReference(message_1, field, &scratch1),
113 reflection_2->GetStringReference(message_2, field, &scratch2)));
114 }
115 break;
116 case FieldDescriptor::CPPTYPE_UINT32:
117 COMPARE_FIELD(UInt32);
118 case FieldDescriptor::CPPTYPE_UINT64:
119 COMPARE_FIELD(UInt64);
120
121 #undef COMPARE_FIELD
122
123 case FieldDescriptor::CPPTYPE_MESSAGE:
124 return RECURSE;
125
126 default:
127 GOOGLE_LOG(FATAL) << "No comparison code for field " << field->full_name()
128 << " of CppType = " << field->cpp_type();
129 return DIFFERENT;
130 }
131 }
132
SetDefaultFractionAndMargin(double fraction,double margin)133 void DefaultFieldComparator::SetDefaultFractionAndMargin(double fraction,
134 double margin) {
135 default_tolerance_ = Tolerance(fraction, margin);
136 has_default_tolerance_ = true;
137 }
138
SetFractionAndMargin(const FieldDescriptor * field,double fraction,double margin)139 void DefaultFieldComparator::SetFractionAndMargin(const FieldDescriptor* field,
140 double fraction,
141 double margin) {
142 GOOGLE_CHECK(FieldDescriptor::CPPTYPE_FLOAT == field->cpp_type() ||
143 FieldDescriptor::CPPTYPE_DOUBLE == field->cpp_type())
144 << "Field has to be float or double type. Field name is: "
145 << field->full_name();
146 map_tolerance_[field] = Tolerance(fraction, margin);
147 }
148
CompareDouble(const FieldDescriptor & field,double value_1,double value_2)149 bool DefaultFieldComparator::CompareDouble(const FieldDescriptor& field,
150 double value_1, double value_2) {
151 return CompareDoubleOrFloat(field, value_1, value_2);
152 }
153
CompareEnum(const FieldDescriptor & field,const EnumValueDescriptor * value_1,const EnumValueDescriptor * value_2)154 bool DefaultFieldComparator::CompareEnum(const FieldDescriptor& field,
155 const EnumValueDescriptor* value_1,
156 const EnumValueDescriptor* value_2) {
157 return value_1->number() == value_2->number();
158 }
159
CompareFloat(const FieldDescriptor & field,float value_1,float value_2)160 bool DefaultFieldComparator::CompareFloat(const FieldDescriptor& field,
161 float value_1, float value_2) {
162 return CompareDoubleOrFloat(field, value_1, value_2);
163 }
164
165 template<typename T>
CompareDoubleOrFloat(const FieldDescriptor & field,T value_1,T value_2)166 bool DefaultFieldComparator::CompareDoubleOrFloat(const FieldDescriptor& field,
167 T value_1, T value_2) {
168 if (value_1 == value_2) {
169 // Covers +inf and -inf (which are not within margin or fraction of
170 // themselves), and is a shortcut for finite values.
171 return true;
172 } else if (float_comparison_ == EXACT) {
173 if (treat_nan_as_equal_ &&
174 MathLimits<T>::IsNaN(value_1) && MathLimits<T>::IsNaN(value_2)) {
175 return true;
176 }
177 return false;
178 } else {
179 if (treat_nan_as_equal_ &&
180 MathLimits<T>::IsNaN(value_1) && MathLimits<T>::IsNaN(value_2)) {
181 return true;
182 }
183 // float_comparison_ == APPROXIMATE covers two use cases.
184 Tolerance* tolerance = FindOrNull(map_tolerance_, &field);
185 if (tolerance == NULL && has_default_tolerance_) {
186 tolerance = &default_tolerance_;
187 }
188 if (tolerance == NULL) {
189 return MathUtil::AlmostEquals(value_1, value_2);
190 } else {
191 // Use user-provided fraction and margin. Since they are stored as
192 // doubles, we explicitly cast them to types of values provided. This
193 // is very likely to fail if provided values are not numeric.
194 return MathUtil::WithinFractionOrMargin(
195 value_1, value_2, static_cast<T>(tolerance->fraction),
196 static_cast<T>(tolerance->margin));
197 }
198 }
199 }
200
ResultFromBoolean(bool boolean_result) const201 FieldComparator::ComparisonResult DefaultFieldComparator::ResultFromBoolean(
202 bool boolean_result) const {
203 return boolean_result ? FieldComparator::SAME : FieldComparator::DIFFERENT;
204 }
205
206 } // namespace util
207 } // namespace protobuf
208 } // namespace google
209